Project Summary Salt/water balance is crucial to mammalian physiology. Overconsumption of salt has been linked with health problems, particularly hypertension. Development of salt taste substitutes or enhancers has been ineffective partly due to the incomplete knowledge of the receptors and other signal transduction components responsible for salt taste. While an epithelial sodium channel has been shown to be involved in the amiloride-sensitive salt taste transduction, the amiloride-insensitive (AI) salt taste transduction mechanism remains to be elucidated. The goal of this proposed research is to advance our understanding of salt taste by identifying the AI salt transduction components. We will functionally characterize taste bud cells and identify and individually collect AI salt-responsive type II bitter receptor cells and AI salt type III taste bud cells as well as control cells salt-unresponsive type II and III cells, respectively (Aim 1). We will amplify and interrogate these single cells' transcriptomes using deep sequencing, and identify genes that are preferentially expressed in the salt-responsive AI type II and III cells. We will perform in-depth bioinformatic analysis on these differentially expressed genes to identify candidate AI salt receptor genes (Aim 2). The role of these candidate genes in the AI salt taste will be further investigated in our follow-up studies. Results from these studies can fill an important gap in understanding salt taste sensation and perception, thus leading to effective means to reduce salt consumption.